Sewing machine attachment for spiral seams



Nov. 28, 1961 E. DELLA ROSSA 3,010,414

SEWING MACHINE ATTACHMENT FOR SPIRAL SEAMS Filed Feb. 18, 1958 3 Sheets-Sheet l O a5- 29 31 30 35 6 as 27 Nov. 28, 1961 E. DELLA ROSSA 3,010,414

SEWING MACHINE ATTACHMENT FOR SPIRAL SEAMS Filed Feb. 18, 1958 5 Sheets-Sheet 2 Nov. 28, 1961 E. DELLA ROSSA SEWING MACHINE ATTACHMENT FOR SPIRAL SEAMS 3 Sheets-Sheet 3 Filed Feb. 18, 1958 g @H- "i lie a l 2 I4 United States Patent 3,010,414 SEWING MACHINE ATTACHMENT FOR SPIRAL SEAMS Emilio Della Rossa, corso della Vittoria, Novara, Italy Filed Feb. 18, 1958, Ser. No. 715,972 Claims priority, application Italy Feb. 23, 1957 7 Claims. (Cl. 112-2) This invention relates to sewing machines and more particularly to a sewing machine attachment for spiral seams.

In many uses of sewing machines, such as the manufacture of brassieres, spiral seams are required for imparting a certain stiffness to the fabric. The sewing of spirals is at present carried out by hand and requires semi-skilled workers. Nevertheless, the spiral is not always perfectly formed even by such workers.

It is a principal object of this invention to provide a sewing machine attachment by means of which a spiral seam may be easily effected even by non-skilled workers or machine operators.

The improved attachment comprises a carriage movable along a path substantially perpendicular to the line of feed of the sewing machine needle. Means are provided for anchoring to the carriage a fabric or workpiece region at the pole or center of the spiral seam to be eifected on the fabric, though allowing the fabric to rotate about said pole and means are included for imparting a translational movement to the carriage in a timed relationship with rotational movement of the fabric efiected by the original feeding means on the sewing machine.

The invention will be described with reference to the accompanying drawings which show by way, of example an embodiment thereof.

FIG. 1 is a perspective view partly in section of a sewing machine provided with the attachment according to the invention;

FIG. 2 is a fragmentary perspective view on an enlarged scale of a portion of the machine shown in FIG. 1 as seen from below;

FIG. 3 is a side view, partly in section, of the carriage and guides therefor according to the invention;

FIG. 4 is a sectional view of the carriage taken on line IV--IV of FIG. 3;

' FIG. 5 in an axial sectional view of the means for imparting a translational movement to the carriage;

FIG. 6 is an elevation view on an enlarged scale of a detail not shown in FIG. 5 of the means for displacing the carriage;

FIG. 7 is an axial sectional view of the means for anchoring to the carriage the point on the fabric which lies at the center of the spiral seam, and

-FIG. 8 is a view, on an enlarged scale partly in section, of a detail of FIG. 7.

FIG. 1 shows a conventional sewing machine having a working table P, an arm B and a head T.

The attachment for sewing spirals comprises a plate 1 which is secured to the working table P. Guides 2 are secured to the plate 1 for guiding a carriage 3 movable lengthwise of the guides. The carriage 3 has secured thereto pins 4 for rollers 5 which roll on the guides 2.

The guides 2 are arranged to guide the carriage along a path substantially normal to the path of reciprocation of the sewing machine needle (not shown on the drawing).

The fabric workpiece on which a spiral seam is to be sewn, is anchored to the carriage at a pivot point on the fabric lying at the center of the spiral seam to be sewn on the fabric. The fabric workpiece is held so that'it is freely rotatable about this point. The anchoring means 3,010,414 Patented Nov. 28, 1961 for the fabric to the carriage are generally denoted by A in FIGURE 1 and shall be described hereafter.

' The carriage 3 is fed along the guides 2 'by means of a device generally denoted in FIGURE 1 by letter E, to be described hereafter.

Operation of the sewing machine rotates the fabric about the pivot point at which the fabric is anchored to the carriage, feeding of the carriage effecting in turn a translational movement of the point about which the fabric rotates, which results ultimately in a spiral seam.

The translational movement of the carriage is suitably timed with the angular rotation of the fabric efifected by the original feed means on the machine.

The device effecting the translational movement of the carriage is conveniently drivingly connected with an original movable member of the sewing machine.

The device effecting the translational movement of the carriage comprises a threaded portion 6 fixed on a rotary shaft 29 which is rotatable in a support 7 secured to the sewing machine frame, and a nut 8 comprising one screw thread portion of limited length adapted to be engaged between two consecutive threads on the threaded portion 6.

The nut 8 is secured to the end of a rod 9 which is axially movable in a tubular extension 10a having a control knob 10.

The rod 9 is biased outwardly of the tubular extension 10:: by a spring 11 enclosed by the tubular extension.

The extension 10a is movable in a guide 12 fixed to a plate 13 which is in turn secured by means of screws 14 to the carriage 3.

A spring 15 is enclosed in the guide 12 and is arranged to push the tubular extension 104 towards a position in which the screw thread on the nut 8 is released from the threaded portion 6.

In order to hold the screw thread on the nut 8 engaged in the portion 6 a pawl 16 is provided, which cooperates with a notch 10b formed in a flattened portion on the control knob 10. The pawl is biased to its engaged position in the notch by a spring 17. The pawl 16 is slidably guided in a suitable recess in the carriage 3 and can be released from the notch 10b by manual operation of a member 18 secured thereto.

The carriage 3 has moreover secured thereto by means of screws 19 a support 20 for a disk 21 formed with a recess 21a adapted to receive a pin 22 associated with the device anchoring the fabric to the carriage.

The nut 8 is shown in FIGURE 3 in its disengaged position. Engagement with the threaded portion 6 is effected by depressing the knob 10, whereby the pawl 16 snaps into the notch 10b and holds the nut 8 lowered. Should during this movement the screw thread on the nut 8 not hit a recess between consecutive threads on the portion 6, the rod 9 is withdrawn into the tubular extension 10a against the actionof the spring 11. As soon as the threaded portion 6 starts rotating, the screw thread on the nut 8 is free to snap between two screw threads on the threaded portion'6. Y In order to disengage the nut 8 from the threaded portion 6 the member 18 should merely be pushed to the right as seen on the drawing thereby releasing the pawl 16 from the notch 10b; under these conditions the spring 15 again lifts the knob, thereby releasing the nut 8 from the threaded portion 6. g

The threaded portion 6 is rotatably driven from an original movable member on the sewing machine through suitable transmission means. The movable member is conveniently in the form of a rocking shaft 23 which drives the feed mechanism on the machine. The shaft 23 is driven from a shaft H through a coupling connection comprising "an eccentric W fixed on the shaft H and engaged by a fork C on the end of a lever pivotally con- 3 nected at the opposite end to an arm G secured to the shaft 23. Rortation of the shaft H imparts oscillatory movement to the shaft 23. The amplitude of the oscillations of the lever provided with the fork C is controlled by a shoe D pivotally mounted on the lever and slidable in a guide E on a pivotally mounted lever F. Adjustment of the position of the lever F controls the position of the guide and, therefore, the travel of the shoe D.

The means for transmitting motion from the shaft 23 to the threaded portion 6 comprises (FIGS. 2 and 7) a first arm 24 which is keyed to the shaft 23 and is coupled by a connecting rod 25 to a second arm 26 keyed to an idle shaft 27. The latter drives the portion 6 through a device adapted to convert its angular reciprocating motion to an intermittent rotation in one direction only of the portion 6. In addition to imparting rotation to element 6 the shaft moves the work feed which retates the fabric feed about a tip 22 by mechanism according to the United States Patent 2,716,952.

The aforementioned converting device (FIG. comprises a first free wheel adapted to couple the shaft 27 with the shaft 29 when the shaft 27 rotates in one direction and a second free wheel arranged to prevent movement of the shaft 29 in a direction opposite the direction in which the shaft 29 is carried along by the idle shaft.

The first free wheel comprises a driving member 28 keyed to the idle shaft 27 and a driven member in the form of a ring 32 secured to a flange on a flanged sleeve 31 keyed to the shaft 29. The ring 32 moreover serves as a driving member for the second free wheel, the driven member of which, denoted by 30, is secured on a hollow shaft 34 whichvis fixed in a support 35. A flange 33 secured to the ring 32 and rotatable about the hollow shaft 34 seals the two free wheels.

The driving member 28 on the first free wheel engages the ring 32 when the shaft 27 rotates in one direction, the second free wheel allows rotation of the shaft 29 in the direction in which it is carried along by the shaft 27 4 to swing and be positioned in a plane extending through the sewing needle axis and the path of the carriage.

A helical spring 52 encircles the rod 64 within the guide 45 and bears at one end against a shoulder 45]) formed within the guide 65 and at its opposite end against a bushing 53 secured by means of a screw 54 on the rod 64.

The spring 52 is arranged to bias the rod 64 towards the position in which the pin 22 is withdrawn from the fabric.

The rod 64 is held in its fabric engaging position by a pawl 55 of beam shape pivoted at 56 having a tooth 55a adapted to extend into a hole in the guide 65 and engage the bushing 53 in order to hold the rod 64 in its fabric engaging position. The pawl 55 is held in position engaging the bushing'53 by a spring 57.

On completion of the spiral seam the arm of the beam 55 remote from the tooth 55a engages a stationary stop 58 carried by the support 47 and releases the rod 64 which snaps upwardly, whereby the fabric is automatically released on completion of stitching.

It will be understood that I do not wish to limit myself to the embodiments and constructional details described and shown above, which can be widely varied within the principle of my invention without departing from scope thereof.

What I claim is:

1. An attachmentfor a sewing machine having stitchforming means including a reciprocating needle, means for feeding material past said stitch-forming means in a predetermined direction, and drive means, said attachment comprising; a frame, a work-controlling pivot member slidable on said frame in a direction transverse to said predetermined direction, a threaded rotary shaft on said frame extendingparallel' to said transverse direction, connecting means adapted to form a driving connection from said drive means to said shaft for intermittently rotating said shaft through a small angle in one direction,

through the first free wheel but precludes its rotation in i an opposite direction.

The ends of the connecting rod 25 are articulated to sleeves 36, 37 respectively (FIGURE 6). The sleeve 36 is slidable along the arm 26 and can be held in position by a screw 38. v

The sleeve 37 is likewise slidable along the arm 24 and carries a disk 39 which isbiased against a cam 40 by a helical spring '41 encircling thearm 24 and acting on the sleeve 37.

The cam 40 is secured to a strap 42a keyed to the end of a rod 42 movable in guide sleeves 43 secured to the support 7 and has keyed thereto by means of a sleeve an arm 44 secured to the guide 12 for the tubular extension 10a.

nut means engaging the threads of said shaft and drivingly connected to said work-controlling pivot member whereby said pivot member is intermittently moved in said transverse direction, said drive means including an oscillatory member, said connecting means comprising; a rockable member, a one-way clutch drivingly connecting said rockable member to said threaded shaft, a radial arm on said rockable member, a driving arm mounted on said oscillatory member, and link means pivoted to said driving arm and said radial arm, and further means responsive to movement of said pivot member for progressively changing the magnitude of successive rotations of said shaft.

2. In a detachable spiral stitching attachment forsew- 7 ing machines, the machine having a reciprocably driven The cam 40 is thereby rigidly connected with the carable in a guide which is provided with a projection or a pivot 45a rotatable in a bushing 46 secured to a support 47 attached to thehead T of the sewing machine. The lower end of the rod 64 is enclosed by a head 48 carrying a depending support 49 for a pin 22 adapted to pierce the fabric and fit into'the notch 21a in the disc 21 mentioned above. e

The head 48- is slidable along the rod 64 against the action of a compression spring 50. The rod 64 'is provided with dowels 51 movable in slots 4811 cut in the head 48. V

'I'he pivot 45a rotable in the bushing 46 is arranged for allowing movement of the guide 65, hence the rod 64 needle, and feed mechanism, in combination, a carriage slidable in a direction perpendicular to the line of reciprocation of the sewing machine needle, means to releasably secure a workpiece for pivotal rotation relative to said carriage at a pivotal point corresponding substantially to a point about which the workpiece is pivotally rotated, said means to releasably secure a workpiece to said carriage including means to automatically release the workpiece when the spiral has been stitched on the workpiece, means operably connectable to said feed mechanism and operably driven therefrom for effecting intermittent translational movement of the carriage in said direction in timed relationship with the angular rotation of the workpiece, said means for effecting the translational movement of the carriage comprising a threaded rotary shaft driven intermittently in one direction only,

ment comprising; a frame, a work-controlling pivot member slidable on said frame in a direction transverse to said predetermined direction, a threaded rotary shaft on said frame extending parallel to said transverse direction, connecting means forming a driving connection from said drive means to said shaft for intermittently rotating said shaft through a small angle in one direction, nut means selectively engageable with the threads of said shaft and drivingly connected to said work-controlling pivot mem ber whereby said pivot member is intermittently moved in said transverse direction, means operable selectively to engage said nut with said thread, said drive means including an oscillatory member, said connecting means comprising; a rockable member, a one-way clutch drivingly connecting said rockable member to said threaded shaft, a radial arm on said rockable member, a driving arm mounted on said oscillatory member, and link means pivoted to said driving arm and said radial arm, and means responsive to movement of said pivot member for progressively changing the magnitude of successive rotations of said shaft.

4. An attachment for a sewing machine having stitchforming means including a reciprocating needle, means for feeding material past said stitch-forming means in a predetermined direction, and drive means, said attachment comprising; a frame, a work-controlling pivot member slidable on said frame in a direction transverse to said predetermined direction, a threaded rotary shaft on said frame extending parallel to said transverse direction, connecting means adapted to form a driving connection from said drive means to said shaft for intermittently rotating said shaft through a small angle in one direction, nut means selectively engageable with the threads of said shaft and drivingly connected to said Work-controlling pivot member whereby said pivot member is intermittently moved in said transverse direction, means operable selectively to engage said nut with said thread including means to releasably lock said nut in engagement with said threads of said shaft, said drive means including an oscillatory member, said connecting means comprising; a rockable member, a one-way clutch drivingly connecting said rockable member to said threaded shaft, a radial arm on said rockable member, a driving arm mounted on said oscillatory member, and link means pivoted to said driving arm and said radial arm, and means responsive to movement of said pivot member for progressively changing the magnitude of successive rotations of said shaft.

5. An attachment for a sewing machine having stitchforming means including a reciprocating needle, means for feeding material past said stitch-forming means in a predetermined direction, and drive means, said attachment comprising; a frame, a work-controlling pivot member slidable on said frame in a direction transverse to said predetermined direction, a threaded rotary shaft on said frame extending parallel to said transverse direction, connecting means forming a driving connection from said drive means to said shaft for intermittently rotating said shaft through a small angle in one direction, nut means engaging the threads of said shaft and drivingly connected to said work-controlling pivot member whereby said pivot member is intermittently moved in said transverse direction, said drive means including a driven member, said connecting means comprising; a rockable member, a one-way clutch drivingly connecting said rockable member to said threaded shaft, a first arm on said rockable member, a driving member mounted on said driven member, and link means pivoted to said driving member and said first arm, and means responsive to movement of said pivot member for progressively changing the magnitude of successive rotations of said shaft.

6. An attachment for a sewing machine having stitchforming means including a reciprocating needle, means for feeding material past said stitch-forming means in a predetermined direction, and drive means, said attachmerit comprising; a frame, a work-contro1ling pivot member slidable on said frame in a direction transverse to said predetermined direction, a threaded rotary shaft on said frame extending parallel to said transverse direction, connecting means adapted to form a driving connection from said drive means to said shaft for intermittently rotating said shaft through a small angle in one direction, nut means engaging the threads of said shaft and drivingly connected to said wo-rkcontro1ling pivot member whereby said pivot member is intermittently moved in said transverse direction, said drive means including a driven member, said connecting means comprising a one-way clutch drivingly connecting said driven member to said threaded shaft, and means responsive to movement of said pivot member for progressively changing the magnitude of successive rotations of said shaft.

7. An attachment for a sewing machine having stitchforming means including a reciprocating needle, means for feeding material past said stitch-forming means in a predetermined direction, and drive means, said attachment comprising; a frame, a work-controlling pivot member slidable on said frame in a direction transverse to said predetermined direction, a threaded rotary shaft on said frame extending parallel to said transverse direction, connecting means adapted to form a driving connection from said drive means to said shaft for intermittently rotating said shaft through a small angle in one direction, nut means in operation engageable with the threads of said shaft and drivingly connected to said Work-controlling pivot member whereby said pivot anember is intermittently moved in said transverse direction, means operable to selectively engage said nut with said thread, said drive means including an oscillatory member, said connecting means comprising a one-way clutch drivingly connecting said oscillatory member to said threaded shaft, and means responsive to movement of said pivot member for progressively changing the magnitude of successive rotations of said shaft.

References Cited in the file of this patent UNITED STATES PATENTS 1,462,168 Denemark July 17, 1923 2,437,624 Sutker Mar. 9, 1948 2,551,261 Gensheimer May 1, 1951 2,730,055 Desperak et a1 J an. 10, 1956 2,863,407 George Dec. 9, 1958 

